Luminor Chrono 40mm
The Luminor Chrono was introduced in 2000 (C) in two styles, strap and bracelet. The model was "tested" however in 1999 (B) with PAM 52, which varies from the current models in that it had no date. The case is a relatively standard Luminor 40mm one, with chronograph pushers recessed into the crown-lock.
For the E series (2002) two new chronographs were introduced, which are identical to earlier models with the exception of the fact that they have grey instead of black dials.
The chronos use the automatic OP IV movement.
A "full size" 44mm chronograph was introduced in 2003 for the F series.
Also as of the F series / 2003 it looks like the OP IV movement is no more, and hence this whole line. The PAM 121 and 122 and not featured in the 2003 catalogue; were they ever produced? I have only ever seen prototypes.